{ "id": "2411.10767", "version": "v1", "published": "2024-11-16T10:17:42.000Z", "updated": "2024-11-16T10:17:42.000Z", "title": "Green's formula and Derived Hall algebras", "authors": [ "Ji Lin" ], "comment": "24pages", "categories": [ "math.RT" ], "abstract": "The aim of this note is to clarify the relationship between Green's formula and the associativity of multiplication for derived Hall algebra in the sense of To\\\"{e}n (Duke Math J 135(3):587-615, 2006), Xiao and Xu (Duke Math J 143(2):357-373, 2008) and Xu and Chen (Algebr Represent Theory 16(3):673-687, 2013). Let $\\mathcal{A}$ be a finitary hereditary abelian category. It is known that the associativity of derived Hall algebra $\\mathcal{D}\\mathcal{H}_t(\\mathcal{A})$ implies Green's formula. We show the converse statement holds. Namely, Green's formula implies the associativity of the derived Hall algebra $\\mathcal{D}\\mathcal{H}_t(\\mathcal{A})$.", "revisions": [ { "version": "v1", "updated": "2024-11-16T10:17:42.000Z" } ], "analyses": { "subjects": [ "16E35", "16T10", "18E10" ], "keywords": [ "derived hall algebra", "duke math", "finitary hereditary abelian category", "associativity", "converse statement holds" ], "note": { "typesetting": "TeX", "pages": 24, "language": "en", "license": "arXiv", "status": "editable" } } }